Formulation and optimization of temozolomide nanoparticles by 3 factor 2 level factorial design.

The aim of this study was to investigate the combined influence of 3 independent variables in the preparation of temozolomide bearing Non-PEGylated and PEGylated nanoparticles by emulsification solvent evaporation method. A 3 factor 2 level design was used to derive a polynomial quadratic model and construct contour plots to predict responses. The independent variables selected were concentration of drug (A), concentration of PLGA/PEG-PLGA (B), PVA concentration in aqueous phase (C) and sonication time (D) and evaluated for percentage drug entrapment (PDE) and particle size (PS). A 3(4) factorial design was used with 4 factors (A, B, C and D) at 3 levels and experimental trials were performed at all 82 possible combinations. In the present work, 28 runs are considered as the preliminary trials revealed that on increasing drug concentration from 2.5 to 5 mg the percent drug entrapment increases, but on further increasing the drug concentration (i.e., to 7.5 mg) no significant effect on the percent drug entrapment and particle size was observed. The 3(4) factorial design was used to derive a polynomial quadratic model and construct contour plots to predict responses. Contour plots were constructed to show the effects of A, B, C and D on the PDE and PS.